Inproceedings,
When Visual Programs are Harder to Read than Textual Programs
Proceedings of ECCE-6, page 167--180. (1992)
Abstract
Claims for the virtues of visual programming languages have generally been strong, simple-minded statements that visual programs are inherently better than textual ones. They have paid scant attention to previous empirical literature showing difficulties in comprehending visual programs. This paper reports comparisons between the comprehensibility of textual and visual programs, drawing on the methods developed by Green (1977) for comparing detailed comprehensibility of conditional structures. The visual language studied was LabView, a circuit-diagram-like language which can express conditionals either as `forwards' structures (condition implies action, with nesting) or as `backwards' structures (action is governed by conditions, with boolean operators in place of nesting). Green (1977) found that forwards structures gave relatively better access to `sequential' information, and Gilmore and Green (1984) showed `backwards' structures gave relatively better access to `circumstantial' inf...
